Containment for dispensers

ABSTRACT

A sump for inhibiting leakage of liquid includes a double wall for at least part of the sump, and an interstitial space between the double wall. An indicator liquid is located in the space, and a sensor is in fluid communication with the space such that a change in the pressure or liquid level in the interstitial space causes the sensor to indicate leakage into or from the interstitial space. The double wall includes a base, a wall directed upwardly from the base of the sump, and the upwardly directed wall includes an angular portion being directed at an angle from the base greater than 90 degrees relative to the base. A remote location of that portion is connected with a substantially upright wall portion for the sump. An aperture for an electrical conduit is located in the angular portion.

RELATED APPLICATION

[0001] This application relates to U.S. patent application Ser. No.______ (Attorney Docket No. 21389-11), entitled “DISPENSER CONTAINMENT”,filed contemporaneously with this application. The contents of thatapplication are incorporated by reference herein.

BACKGROUND OF THE INVENTION

[0002] This invention relates to sumps to contain leakages. Inparticular the invention is directed to containing leakages of toxicliquids, such as petroleum or other oil based products. A particularapplication of the technology of the invention relates to protecting theenvironment from gasoline spills at locations where consumers obtaingasoline at dispensers, pumps and the like.

[0003] Current requirements are for periodic testing of leakage aroundgasoline dispensers at consumer gasoline stations. This means thatleakage could occur in between the periods of testing thereby increasingthe oil company's potential liabilities. A reason why current dispensercontainment designs can not be tested continuously is because the insideof a dispenser containment box or sump can not be filled with liquid.The liquid would most likely rust the many components inside the box,and the regulatory agencies do not allow standing fluid and themanufacturers do not allow for the kind of weight that would expose thedispenser sump.

[0004] Visual inspections to see whether the dispenser sump is leakingis impossible. Also it is desirable to change to requiring a higher formof secondary containment and/or monitoring of liquid. A pipe containingthe liquid is termed the first form of containment and the wall of thesump is called the second form of containment.

[0005] Presently there are no regulations that require a tertiary formof containment or a monitoring of the integrity of the secondary ortertiary form of containment. This may change if a product, method orsystem is introduced in the industry with a higher degrees of integrityand protection against leakage than the presently known and usedsystems, methods and products. The present invention is directed toproviding that higher degree or level of containment.

[0006] Testing in California for gasoline station secondary systems isto be at initial installation, six months later and every 3 yearsthereafter. The problem that everyone in the industry faces is how toverify that the system is not leaking. If there is leakage, there is aneed to easily trouble shoot to identify where the leakage problem islocated. At initial installation of a sump with dispenser, testing iseasily accomplished by visually inspecting the box from the outsideprior to cementing over the entire job-site. The problem now faced bythe industry, as a whole is how do you test secondary containment assimply, reliably without major cost to the end user.

[0007] The most commonly used method in the industry is to test thedispenser containment with water filling the containment sump up andutilizing very sensitive float sensors to speed up the test. Thisinvolves filling a dispenser sump up with as much as 50 to 60 gallons ofwater. Should a leak be found the most time consuming issue is thenlocating the leak that can not be viewed from the outside of the sumpsince the containment unit is buried in under concrete. Finding andrepairing a leak is the most time consuming and costly part of thetests. In addition, the water used must then be removed and treated as ahazardous material adding to the cost and complicates the process oftesting.

[0008] Other methods of testing that have been considered were vacuumand pressure testing of dispenser containment which are not practical indispenser containment because of the pipe extending upwards through theopening within the dispenser. The only way to pressurize a conventionaldispenser sump is to remove the dispenser which costs over $1,000 perdispenser and the shutdown of the station.

[0009] Unlike dispenser sumps, tank sumps can be tested under vacuum andpressure because every part contained within a tank sump can be coveredwithout cost. The test is subject to a much more stringent requirementsince air can find much smaller leaks involving electrical wiring leaksand smaller cracks in the sump or its accessories. Air testing usuallyresults in finding leaks in areas that are typically not required totested by regulators.

[0010] The present invention is directed to providing a tertiary form ofcontainment and/or providing a simplified means of monitoringsubstantially easily and/or relatively continuously the second form ofcontainment.

[0011] Another issue relating to sumps, revolves around the need for thepiping containing electrical lines into a hazardous material area to beburied 24″ below a concrete surface and the pipe must be made of acontinuous run or rigid steel conduit. As a result, the electricalfittings are the most commonly damaged fitting. Even flexible fittingsare often bent beyond the recommended entry angle 15 degrees maximum.

[0012] Typically, the worst situation is when an electrician needs torun conduit to the side closest to inside of a dispenser containmentwall. In addition, a typical 90 degrees minimum bend radius may only be8 inches. To compensate for inability to bring an electrical conduitclose to the wall the electrical contractor often over-loops the conduitby 110 degrees and return it back by 20 degrees to align the conduitwith the dispenser above the sump. This typically is a very inaccuratemethod, which then leads the electrical contractor to abuse thepenetration fitting to compensate. This leads to failure of a fitting.An easier method would be to bring the conduit through the bottom of thesump as in shallow pans, which alleviate stress to the fittings.However, this also leaves the fitting on a bottom of a sump exposed tofuels that may breakdown the seals leading to an earlier failure.

[0013] The invention is also directed to having an improved techniquefor passing piping and conduits into and through a sump wall and toretain integrity and alignment with a dispenser above the sump.

[0014] These objects and other objects of the invention are achieved bythe invention in the manner set out below.

SUMMARY OF THE INVENTION

[0015] According to the invention, there is provided a sump forinhibiting leakage of liquid contained therein. There is a double wallfor at least part of the sump. The sump defines a cavity for containingliquid. There is an interstitial space between the double wall. Anindicator liquid is located in the space.

[0016] A sensor is in fluid communication with the interstitial spacesuch that a change in the pressure or liquid level in the interstitialspace causes the sensor to indicate leakage into or from theinterstitial space.

[0017] Also according to the invention the sump includes a base, and awall directed upwardly from the base of the sump towards the top,thereby forming a cavity for liquid.

[0018] An angular portion of the upwardly directed wall is directed atan angle from the base greater than 90 degrees and a remote location ofthat angular portion is connected with an upright wall to the sump.

[0019] According to the invention there is provided a system ofdispenser containment utilizing a primary, namely an inner, and asecondary, namely an outer, wall. An interstitial space between the twowalls traps an interstitial fluid to test the integrity of the dispensercontainment and the fittings that pass through the walls.

[0020] Preferably a minimized quantity of fluid is located in theinterstitial space. This is achieved by retaining the interstitial spaceas relatively small as possible. This makes the change in the liquidlevel in the space enhance changes in the level to find small leaksquickly.

[0021] In large dispenser sumps {fraction (1/10)} of a gallon changeallows one to visually see a change of 1″ in the level of a manometer orelectronic sensor associated in fluid connection with liquid in theinterstitial space. The interstitial test fluid is permanently leftinside the interstitial space thereby eliminating the need and cost totreat hazardous material cost and virtually eliminating the dispensercontainment tests.

[0022] Preferably, a manometer is employed. The manometer can be used toidentify the height at which a leak can occur. This reduces the time totrouble shoot. The manometer can be used to measure small volume changeseither visually or through electronic float sensors. The visualinspections are performed without the introduction of any water insideof the dispenser sump. The manometer can permit for visual or electronicmonitoring on an intermittent basis or on a continuously basis.Manometers are also preferred because the amount hydraulic pressure isrelatively limited by the height over the lowest point.

[0023] The manometer is removable because the manometer may be damagedand require to be replaced. Plastic is a preferred material because ifduring the installation a pipe wrench hit the tubing, the manometer maybreak before causing damage to the more expensive containment sump.

[0024] The manometer placement at the lower part of the sump ispreferred. Testing of the sump with air pressure or vacuum or evenhelium requires the interstitial fluid must be removed first from thelowest point in the dispenser containment interstitial. Once removed,the alternative tests are helpful in pinpointing leaks within the sump.

[0025] The secondary wall, namely the outer wall, also allows relativelyeasier trouble shooting using a variety of methods such as manometermeasurement, or pressure/vacuum or helium measurement.

[0026] Should a sump box leak somewhere on the outside it is likelythere was no release of gasoline to the ground because of the redundantseals in a double wall dispenser containment. Repair to dispenser sump'sfittings is a common problem and is easily repaired inside dispensercontainment with the present invention.

[0027] Brine or Propylene Glycol solution is the preferred interstitialfluid because of the reduced likelihood of damaging effects of liquidfreezing, namely expanding, within the interstitial of double walldispenser containment and it is non-toxic. When filling the dispensercontainment with brine solution as purging air from the upper extremityis effected. A breathing hole allows air to escape and allows the brineto completely fill the interstitial space. The purging of air preventsvolume fluctuations due to air temperature fluctuations. This helpsminimize false alarms especially on double wall dispenser containmentwith electronic level detectors.

[0028] A breather hole may need to be open because it will show leakagebetter. In other cases, the hole is closed to ensure a more redundantlysealed system.

[0029] The configuration of container on the sump box with an angularportion has an internal angular relationship with adjacent walls oneither side of about 135 degrees and has advantages. This degreesrelationship is akin to an outside angular relationship of 45 degreesangle at the bottom of the sump box and the upright of the sump box.This relationship has valuable beneficial advantages to an electricalcontractor fitting electrical conductors and pipes in and through thesump box.

[0030] The foregoing and other objects, features, and advantages of thepresent invention will be apparent from the following detaileddescription of the preferred embodiments which makes reference toseveral drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031]FIG. 1 is a cross-sectional view of a sump illustrating the doublewall interstitial space manometer connected with the interstitial space,the gas line or pipe in and out of the sump and the electrical conduitin and out of the sump.

[0032]FIG. 2 is an enlarged sectional view showing the double wall andthe interstitial space.

[0033]FIG. 3 is a prior art representation of a sump embedded inconcrete, the sump being single walled and having an electrical conduitarcing from outside the sump, through the sump and into the body of thesump.

[0034]FIG. 4 is a cross-sectional view of a different prior artconfiguration of a sump buried in concrete, the sump being singlewalled, and having two other configurations of an electrical conduitentering the sump from outside, the conduit passing through a fittingand arcing upwardly in the sump.

[0035]FIG. 5 is a representation of a fitting passing through the doublewall of a sump, the fitting being for receiving a gas line.

[0036]FIG. 6 is a cross-sectional representation of a fitting passingthrough a double wall sump, the fitting being for passage of anelectrical conduit.

[0037]FIG. 7 is a representation of an interstitial wall fluidlyconnected with a column and having a sensor in the column to determinevariations of liquid pressure or volume in the interstitial space, thesensor being connected with an indicator.

[0038]FIG. 8 is a cross-sectional side view of the sump showing theinterstitial wall, three parts for three different gas lines to enterthe sump, and a manometer located at one end of the sump.

[0039]FIG. 9 is a cross-sectional view of the sump as viewed from thetop showing three gasoline inlets, three gasoline outlets, and twoapertures for receiving electrical conduits and a test manometer locatedtoward one side of the sump.

[0040]FIG. 10 is a cross-sectional view of a tank sump according to theprior art.

[0041]FIG. 11 is a cross-sectional view of a tank sump with a bottom forcontainment

[0042]FIG. 12 is a cross-sectional view of a tank sump with a doublewall and bottom and interstitial space for containment.

[0043]FIG. 13 is a cross-sectional side view of a sump showing theinterstitial wall, one port for a gas line to enter the sump, anelectronic float sensor with a manometer located at one end of the sump,and an electronic sensor for secondary containment.

[0044]FIG. 14 is a cross-sectional side view of part of a sump showingthe interstitial wall, a float sensor with a manometer, and a mechanicallinkage between the sensor and a valve for operating the shut off valve.

[0045]FIG. 15 is a different version of monitor with the sump.

[0046]FIG. 16 is a version of monitor outside the sump.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0047] In the following description of the preferred embodimentsreference is made to the accompanying drawings which form the partthereof, and in which are shown by way of illustration of specificembodiments in which the invention may be practiced. It is to beunderstood that other embodiments may be utilized and structural andfunctional changes may be made without departing from the scope of thepresent invention.

[0048] A sump for inhibiting leakage of liquid contained thereincomprises a double wall for at least part of the sump. The sump definesa cavity for containing liquid. There is an interstitial space betweenthe double wall and there is a fluid in the interstitial space. A sensoris in fluid communication with the fluid in the interstitial space suchthat a change in the condition of the fluid in the interstitial spacecauses the sensor to indicate leakage into or from the interstitialspace.

[0049] There are means for locating a gasoline dispenser above the sump,the sump being for containing liquid leaking from at least one of thedispenser or a pipe directed from a source of gasoline to the gasolinedispenser and the pipe being directed at least partly through the sumpin its connection between the source and the dispenser.

[0050] The sensor is a manometer, and the manometer is selectivelymounted in the cavity within an inner wall of the double walls andwherein the manometer is in fluid communication with the interstitialspace. An indictor fluid is a liquid, and the indicator liquid ispreferably brine, the brine being selectively colored. The brine extendsfrom the interstitial space into a manometer. The manometer is mountedat the base of the sump and is directed substantially vertically withinthe sump, and the manometer includes a substantially transparent columnwhereby the brine level can be sensed.

[0051] There is a measure mounted in adjacency with the manometer columnsuch that changes in the liquid level in the manometer can be detectedagainst a measuring scale. The manometer is separable from the sump,separation being effected by releasing a mounting element. The mountingelement is located with the base of the sump and extends between aninner wall through the interstitial space and to an outer wall of thesump. The manometer column is made of plastic.

[0052] The interstitial space is retained relatively small thereby topermit a relatively small quantity of interstitial fluid to be containedtherein such that relatively small changes in fluid condition in theinterstitial space. Such changes are affected either by the ingress offluid from the cavity through an inner wall to the interstitial space orthe egress of fluid from an outer wall to an area surrounding the outerwall. This makes it relatively easily detected by changes reflected inthe manometer.

[0053] The interstitial space includes bridges, the bridges selectivelybeing formed by fiberglass and the bridges acting to provide enhancedstrength collectively to inner and outer walls of the sump. The outerwall of the interstitial space extends in height up at least up toone-half the height of an inner wall of the sump. The outer wall extendsto a height above the level of a fitting for located tubing passingthrough the outer wall and the inner wall of the sump wall.

[0054] A breathing hole can be located towards the upper limit of theinterstitial space, the breathing hole permitting purging of airrelative to the interstitial space, thereby to minimize volumefluctuations in fluid level in the interstitial space due to temperaturedifferences.

[0055] The double wall includes a base, a wall directed upwardly fromthe base of the sump towards the top thereby forming a cavity forliquid, and the upwardly directed wall includes an angular portion beingdirected at an angle from the base greater than 90 degrees relative tothe base and a remote location of that portion being connected with asubstantially upright wall portion for the sump. The angular portionextending between the base and the substantially upright wall portionextends at about 135 degrees relative to the base and at about 135degrees relative to an upright wall of the sump. The sump is essentiallyfour sided, namely a base, a first upright wall, a second upright wall,and the angular portion between the base and one of the upright walls.

[0056] There is an aperture through the angular portion. The apertureincludes a fitting for receiving a conduit, the conduit being directedsubstantially at right angles to the angular portion. The conduitincludes a bend within the sump, the bend being for directing theconduit substantially upwardly and parallel to a upright wall of thesump. There is also a bend in the conduit in a position removed from thefitting and outwardly located relative to the sump such that the conduitportion after the bend is directed substantially parallel to the base ofthe sump. The bend in the conduit in a position removed from the fittingand outwardly located relative to the sump is such that the conduit isdirected substantially parallel to the base of the sump. The conduit isintegral and continuous between a position removed from the sump andcrosses through an aperture in the sump and upwardly in the sump.

[0057] The cross section of the sump viewed from the top issubstantially rectangular. An end view of the sump includes asubstantially horizontal top, a vertical side wall, the base extendingsubstantially parallel to the top and for a distance partially equal tothe distance of the top. The angular portion extends upwardly to a lineabout equal to the end of the top, and there is a vertically directedrelatively shorter upwardly directed wall extending between the end ofthe top and the end of the angular portion remote from the base.

[0058] There is at least one aperture in the upright wall. The apertureis to receive a pipe containing fluid and for directing the pipe throughthe sump wall and upwardly to a position above the sump, the uprightwall being the wall not directly connected to the angular portion of thesump.

[0059] There is also an aperture in the angular portion, the aperturebeing in a position relatively closer to the upright wall connected tothe angular portion than to the position of joinder of the angularportion with the base.

[0060] The sump includes a mouth at the top, the mouth being forreceiving a gasoline dispenser and means for passage through the sump ofone or more pipes connecting the gasoline dispenser with the environmentoutside of the sump. One pipe is for directing gasoline from anenvironment outside of the sump through the sump and to the dispenserand including a conduit for directing electrical conductors from anenvironment outside of the sump through the sump to the dispenser.

[0061] The electrical conduit includes a vertically directed portion, aportion angled at about 135 degrees relative to the vertical portion andpassing through an aperture in the angular portion of the sump, and afurther bend in the conduit of about 135 degrees at a position remoteand outside of the sump, the conduit being for directing electricalconductors from outside of the sump through the sump and above the sump.

[0062] A sump 10 for inhibiting the leakage of liquid from the sumpincludes an inner wall 12 and an outer wall 14. Between these walls 12and 14 there is an interstitial spatial member 16. The outer wall 14 canbe formed of a suitable metal. The inner wall 12 can be of a fiberglassor other material or vice versa or both can be of fiberglass or othersuitable synthetic material. The interstitial space 16 forms bridges offiberglass between the walls 12 and 14 and thereby provides extrareinforcing to the walls such that pressure or vacuum applied to theinside of the sump on wall 12 or pressure or vacuum applied on theoutside of wall 12 or the outside of wall 16 reacts against theinterstitial space. The topmost portion of wall 12 above the joined apart 18 between the two walls acts to receive a fitting 20 for receivinga dispenser 22. The dispenser 22 can be for receiving gasoline from acentral reservoir and dispensing that to vehicles.

[0063] With reference to FIG. 5, they can be seen in aperture 24 in thewalls 12 interstitial space 16 and wall 14. The aperture 24 receives afitting 26 which has an outside component 28 and an internal component30. The outside component 28 and internal component 30 are joinedtogether by means of multiple walls which are arranged circumferentiallyaround the aperture 24. The bolts 32 pass through apertures formedaround the main aperture 24. Tightening of the bolts 32 causes thefittings 26 and 30 to be drawn tightly together and thus form aneffective seal around the aperture 24. The members 26 and 30 havelateral flange-like elements 34 and 36, respectively, to affect the sealagainst the outer wall 14 and the inner wall 12 as indicated. Throughthe bore 38 passes a gasoline pipe 40. The gasoline pipe 40 is directedtransversely or horizontally as shown in FIG. 1.

[0064] Around the outside of the pipe 40 there is another secondary pipe140 which is engagement with the seals 34 and 36. Between the inside ofthe fitting 26 and the outside of the pipe 40 there is communicationwith the interstitial space 16 so that fluid from the space 16 fillsthat space 142. Thus leakage in the seals 34 and 36 can be determined bychanges in the interstitial space 16.

[0065] There is an elbow 42 within the sump 10 which turns the gasolinepipe upwardly and this is connected with a flexible coupling 44 which isin turn connected to an upwardly directed pipe 46 which exits thefitting 20 and is directed towards the dispenser 22.

[0066] On a different wall of the sump 10, namely an angular projectionwall 48 there is a second aperture 50. The left-hand wall 18 isconnected with a base portion 52 which is then angularly connected atabout 135 degrees with the angular projection 48 of the sump 10. The endremote from the base 52 of the angular portion 48 is connected with theupright wall on the right-hand side of the sump. The angular interiorengagement of the right-hand upwardly directed wall and the angularportion 48 is also about 135 degrees.

[0067] The aperture 50 is located in the angular portion 48 at aposition closer to the right-hand upwardly directed wall of the sump. Inthis fashion, the aperture 24 is fairly far removed from the aperture50, but still at a location sufficient that the apertures can receivethe appropriate conduits or pipes or fittings.

[0068] As described in the embodiment, the sump is shown with theaperture 24 in the left-hand wall and the aperture 50 in the angularportion. In other embodiments, the mirror arrangement can be providedsuch that the right-hand wall can be the elongated wall, the base 252can extend transversely and the angular portion 48 can be directed fromthe base to a shorter left-hand wall. This would depend on differentconfigurations. In yet other forms of the invention instead of thesubstantially right angular configuration illustrated different shapesof sump can be provided. As shown in FIG. 10, the cross section of thesump 10 from the top is substantially right angular. In otherconfigurations, the sump could be substantially circular.

[0069] While the specification describes particular embodiments of thepresent invention, those of ordinary skill can devise variations of thepresent invention without departing from the inventive concept.

[0070] The aperture 50 receives a two-component fitting 52 and 54. Thecomponent fitting 52 is located adjacent to the outside wall 14 and thecomponent fitting 54 is located adjacent to the inside wall 14. Theinterstitial space is located between the walls 12 and 14. An array ofwalls 56 are located circumferentially around the aperture 50 and typingdone off the balls causes the components 52 and 54 to be pulled togetherand thereby effect a seal with sealing portions 58 and 60 which arerespectively pulled tight adjacent to the inside wall 12 and the outsidewall 14 of the sump. A bolt 62 is located through the fitting 52 and 54and this receives in a tight relationship a conduit 64. The conduit 64includes an inlet portion 66 which is substantially horizontallydirected a portion 68 which is substantially bent to be 135 degreesrelative to the line of the inlet portion 66 and a portion 70 which isalso at about 135 degrees relative to the line of the conduit 68. Withthis construct conduit portion 68 penetrates the aperture 50substantially at right angles to the aperture. The fitting 52 and 54have circular clips 72 externally and 74 internally which securestightly the conduit portion 68 with the fitting 52, 54 so that noleakage can occur between the sump 10 and the external portion throughthe fittings 52, 54.

[0071] The fitting 52 and 54 has raised shoulders 152 and 154 which arenot in contact with the conduit 64. Interstitial fluid from theinterstitial space 16 can enter the space 156 formed by the shoulders152 and 154. The space 156 also extends in part between the fittings 52and 54.

[0072] Similarly, the pipe 40 for gasoline which passes through thefitting 26 has one or more circular clips 74 on the outside and 78 onthe inside for sealingly engaging the conduit 40 such that no leakagecan occur between the conduit 40 through the fitting 26.

[0073] With this configuration, the upright portion 70 of the conduit 64is retained relatively close to the right-hand upward wall 12 and is asfar removed as relatively possible from the gasoline conduits 40, 42, 44and 46. The relationship of the portion 68 penetrating the fitting 52and 54 in a right angular fashion is arranged so that no undue pressureis placed due to angular displacement on the members of the fitting 52and 54. Thus, there is no impairment of the sealing quantities of thefitting 52 and 54.

[0074] Mounted on the base portion 252 of the sump is a manometer column80 which is in fluid communication with the interstitial space 16. Asuitable anchorage 82 below the base portion 252 which cooperates with amounting ring 84 affects positive location of the manometer on the base252 of the sump. The manometer column 80 is a sealed glass or plasticcontainer and as such as responsive to the changes in liquid level inthe interstitial space in a manner which is more fully described below.Mounted towards the upper portion of the manometer column 80 is a scaleor reading element 84 which has a rule or measure 18 which issubstantially directed parallel to other measuring lines 86 at the topof the column 80.

[0075] As illustrated in FIGS. 8 and 9, the manometer column 80 islocated towards the end wall 86 of the sump 10. The gasoline apertures24 and their pipes and conduits are located towards the end wall 88 ofthe sump 10. The apertures 50 for the electrical conduit are spacedalong the length 90 of the long walls of the sump such that each of theapertures is about ¼ of the distance from the ends 88 and 86,respectively.

[0076] The interstitial space 16 is filled with a brine fluid whichenters the wall 92 of the column 80 and can be seen in FIG. 1. One ormore apertures can be provided to the interstitial space to permit airto bleed from the interstitial space as necessary. Any leakage in thewall 12 into the interstitial space 16 or leakage in the wall 14 fromthe interstitial space causes the liquid level of the brine in theinterstitial space to change. Those changes are reflected in the changein the height of the liquid in column 92 of the manometer 80. This caneasily be read on the scale 84 of the manometer. The bleed holes wouldbe located near the top of the interstitial space are necessary toremove air from the interstitial space. Once the interstitial is filledwith fluid the variance of pressure or volume due to temperature changewill be negligible so that changes in the level in the column 92 are notdependent on the temperature.

[0077] As illustrated in FIG. 7, there is a different configurationwherein the column 80 includes a sensor 94 which is electricallyconnected through line 96 with an indicator 98. This indication meanspermits for electronic sensing of the changes of the liquid level ofpressure in the column 80.

[0078] The configuration for the electrical conduit 64 provides for acleaner and more effective arrangement than prior art configurations. Asillustrated in FIGS. 3 and 4, there are two prior art configurations foran elliptical conduit 100 entering a sump 102. A sump 102 is buried in aconcrete island 104 which normally mounts a dispenser 106. Theregulations require that the conduit be a fixed distance below thesurface level 108 of the concrete of the road surface 110 or the top ofthe island 104. For this reason, the conduit 100 conventionally has afirst 90 degrees angle 112 which turns the conduit from a horizontaldirection 114 to a substantially perpendicular direction 116. There is asecond bend 118 in the conduit to have a horizontal portion 120 whichpasses through a fitting 122 in the side wall 124 of the sump. There isthen a further 90 degrees bend 126 in the conduit which then turns theconduit to be directed upwardly 128 in the sump. The fitting 122 in thisconfiguration acts with integrity, however, the distance 130 between theupright portion 128 and the wall 124 is substantially extended longerthan is ideal. This places the upright column 128 in the sump portionrelatively too close to gasoline tanks. The requirements are that theconduit 100 be an integral member without any brakes such that there issafety in the electrical leads directed through the ball of the conduit100.

[0079] In FIG. 4 there is a different prior art configuration whichshows a conduit 150 being directed through substantially the sameangular configuration as shown in FIG. 3. However, in order to keep thedistance 152 at a minimum such that the upright portion 154 is closelylocated to the wall 156 the angulation bend 158 is relatively moretightly configured. As illustrated in FIG. 4, the bend interacts withthe end portion 160 of the fitting 162 with an interference effect. Thiscauses the fitting portion 160 to be distorted and to be damaged andthereby not operate efficiently. Additionally as shown, there can be aspace 164 between the electrical conduit 150 when it passes through thefitting 160. This is not a desirable configuration. And yet in nodifferent prior art form there is a conduit 170 which transverseshorizontally below the sump 102 and enters the sump through a base wall172 after making a single right angular bend 174. While thisconfiguration would be acceptable in the sense of preventing leakagebetween the fitting 176 and the conduit 174, it is undesirable to havethe aperture 178 in the base 172 of the sump since this could promoteleakage which otherwise would not occur if the aperture were not in thebase.

[0080] The configuration as illustrated in FIG. 1 shows that the uprightportion 70 of the electrical conduit is more closely related to theupright wall 12 and adequately spaced from the gasoline upright portions44 and 46. Also, by having the appropriate bends in the conduit 64 theportion 68 passes at right angularly through the angular portion 48 sothat the fitting 52 and 54 is not impaired or is maintained withintegrity around the portion 68. The arrangement of having the angularportion 48 interact with the fittings 52 and 54 and the conduit 64 bentinto the three portions 66, 68 and 70 in the manner illustrated in FIG.1 permits for easy installation of the electrical conduit system in thesump in a manner which does not impact the integrity of the assembly andconstruct of the sump 10.

[0081] Many other examples of the invention exist each differing fromthe other in matters of details only. The invention is not to be limitedby the preferred embodiment.

[0082] In some of the preferred embodiments, the fittings for receivingthe gasoline pipes and electrical conduits are constructed partly ofmetal and/or flexible materials such as a suitable plastic or rubber. Inother forms of the invention, the manometer column may be made of a morerigid material such as to be less breakable. A suitable seal is providedat the base of the manometer or other indicator of the liquidrelationship in the interstitial space so as to provide integrity withthe interstitial space and not permit leakage between the interstitialspace and the manometer. The manometer may be located at differentsuitable positions inside the sump and in alternative configurations maybe provided externally to the interstitial space or sump. In differentforms of the invention, different configurations make up theinterstitial space. Fiberglass is provided to form the reinforcingconstruct. In the interstitial space different formations may beprovided. One or other or both of the walls of the sump can be formed ofmetal, fiberglass or other suitable material as required. Differentsensor devices can be used to determine changes in the characteristicsof the fluid in the interstitial space.

[0083] Moreover, different shapes of sump can be used and it can haveapplications in configurations unrelated to dispenses. Accordingly, thesump configuration can be used for determining the change of liquid inany reservoir and for this purpose, the interstitial space in at leastpart of a double wall configuration of the sump or reservoir can be usedas part of the monitoring means when that interstitial space between thedouble wall of a reservoir is connected with a sensor to determinechanges of liquid level or liquid condition in the interstitial space.

[0084] The double walls adds a redundancy protection against the releaseof petroleum products. In addition, the fiberglass process in theinterstitial space bridges across the two walls to increase the wallstrength. This strengthening of walls means less material per dispensercontainment, and is a cost saving. Wall strength is beneficial inpreventing the dispenser sump walls from deforming or cracking due tothe loading from the back filling of the pea gravel. In addition, withthis structural integrity one can also introduce pressure or vacuum tothe two walls to check the integrity of the dispenser containment toquickly verify within the factory environment. Prior to thisverification of sump tightness required filling dispenser sump withliquid which is a time consuming process.

[0085] The invented dispenser containment with two walls means theexterior is a form of tertiary containment. Where the primary wall isthe pipe that carries product, the secondary is the inside wall and thetertiary wall is the exterior.

[0086] This double wall sump box allows one to know if a box is leaking.The continuous test lowers the risk of release to the environmentperhaps saving oil companies from higher liability insurance. Intertiary containment with monitoring system one can actually know if oneof the walls has been compromised. Prior to this containment it wasunknown whether the containment box was liquid tight and if there wasany release of petroleum product.

[0087] Monitoring can be integrated with the piping systems to create asingle monitor system to check dispenser containment, piping systems andtank sump. The monitor can be placed in the dispenser containmentbecause it is normally the highest point, hydraulically, on a pipingsystem. The monitor of the various components of the system can beindividual because testing or monitoring are easier to trouble shoot ifthe systems are independent.

[0088] Is it also possible to introduce other fluids into theinterstitial space. Currently, most studies indicate some thecontamination may be occurring under gasoline stations is happeningthrough permeation. To prevent this a non-toxic additive to the brine orcompletely different fluid that breaks down harmful constituents ofgasoline such as MTBE methyl-tert-Butyl-ether into biodegradablesolutions or chemically bonds to make MTBE to large of a molecule topermeate through the fiberglass/plastic wall. The interstitial space canbe utilized as the barrier or intermediary to prevent furthercontamination of soils. A double penetration fitting is required for adouble wall dispenser containment.

[0089] The 45 degrees bottom allows the electrical fittings to be awayfrom continuous exposure and allows an installer to run conduit on thesame side of the box's entry fitting without stressing the fitting. Theadded benefit is the 45 sump bottom reduces the added bends to conduitthat most deep boxes require. This reduction in bends reduces labor andallows one to run wiring easier through the conduits.

[0090] Although the invention is being described with regard to a sumpwhich is normally located below ground level, the application of theinvention could be with regard to sumps which are above ground and arefor containing liquid. The height of the double wall of the sump canvary. In most cases, there is a double wall base with interstitialspaces and the interstitial spaces in the base are formed with fluidconnection with interstitial spaces in the walls. In some cases, thebase may be totally solid and the double walls with interstitial spacescan be otherwise bound or formed in a rigid anchoring means to the base.The double wall of the interstitial space on the walls alone in thatembodiment is connected with the measuring means to determine the changeof liquid condition and/or level in the interstitial space in the walls.

[0091] The manometer 600 can manifest itself in other forms where thearea to monitor can be void of interstitial fluid. This means actualfluid influx is necessary to detect problems. Since this method is atthe lowest point 601 on the sump, this may be difficult to visually see.The manometer 600 may be an integral part of the sump forming theinterstitial space and point of monitor, and a cap 602 can be used toensure that elements associated with the manometer device 600 are keptessentially dry. As seen in FIG. 15 the air purge point 603 is towardsthe top of the interstitial space and is directed inwardly into thecavity 10. There can be an electronic sensor 604 for measuring any fluidchanges in the cavity of the sump. Within the manometer type device,namely a device which has solid opaque walls there can be an electronicconnection 605 to a remote module associated with an electronic floatsensor 606 located at the low point in and/or about the sump. Theintegral monitor point may provide better protection against damage andan alternative means of testing/trouble shooting the secondary/tertiarywithout removing an interstitial fluid.

[0092] Also the point of monitor may be completely exterior to thecontainment in order to provide remote access. There should be nointerstitial fluid and a common low point from which a sensor mustmonitor that there is no fluid influx implying a possible release ofproduct or water intrusion. This is shown further in FIG. 16, the sensordevice 700, which can optionally be contained in a column 701, isretained dry under normal conditions, and any leakage is transmitted tothe sensor 702, which then transmits a signal along line 703 to anelectronic module.

[0093] The foregoing is a description of the preferred embodiments ofthe invention has been presented for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise form disclosed.

[0094] Many modifications and variations are possible in light of theabove teaching.

[0095] In some cases there can be more components to the sump wall.There can be more angular portions. They can be located on differentsides of the base. Each can have appropriate apertures. In some casesthe sump so formed is used without the interstitial space and/ormanometer measuring system. In other cases the interstitial spacesand/or manometer system can be used without the angular wall portion ofthe sump. The length of the angular portion can vary, and is preferablysufficiently long to accommodate the aperture and fitting andcomfortably. The shortened upright portion is about the same length asthe length of the angular portion.

[0096] The manufacturing of double wall dispenser containment wasinitially thought we would place a plastic mesh sandwich between tocreate an interstitial space between fiberglass walls. Otherconfigurations are double wall plastic boxes. HDPE high-densitypolyethylene boxes can be made in a double-wall configuration in onemold component through a rotational molding process. These may be lessexpensive methods of manufacture.

[0097] Other testing methodologies are pressure and/or vacuum. Howeveras already alluded to this can find leaks that may never occur undernormal working conditions. Helium is a relatively expensive andspecialized method of test.

[0098] The shapes or configurations to this double wall dispensercontainment are limitless. The most typical are rectangular, howeverthis concept can be readily applied to even cylindrical shapes that aretypically applied to tank sumps.

[0099] The manufacturing of double wall dispenser containment uses afoam-core and/or fiberglass product to create the space between the twowalls.

[0100] FIGS. 10-12 show tank sumps that typically consist of largediameter cylinders typically 42″ and 48″. These sumps 301, which workwith tanks 300, consist of multiple fiberglass assemblies that requirefiberglass field application to several of the sumps assemblies or aseach section connects requires a separate assembly.

[0101] The invention provides for the use of sumps 301 with bottoms 302.The benefits of sumps having a bottom to the sump is to allow betterintegrity of the containment sump because the sump need not befiberglass to tank for secondary containment. With a sump having abottom 302, the bottom edge is sealed. This type of vessel may see highhydraulic forces. If the edges of a sump do not keep out all the waterfrom getting under the tank sump the water pressure will seep under thebottom. Since the majority of installations of tank sumps 300 areperformed in the field the conditions and installations lack the controlthat would ensure the bottom is sealed properly. This makes tanks sumpwalls and bottoms critical to handle large hydraulic forces.

[0102] The hydraulic force for water under the sump 301 is equivalent tothe pressure of the water, in high water conditions, 3 ft of waterequals 1.3 pound of force per square inch multiplied by area of sump. Ona 48″ diameter sump the force lifting a sump upwards is 2352 pounds offorce pushing on the bottom of a sump. The tertiary wall design 303 hasa double benefit to strengthen walls of the base of a tank containmentsump and allow testing and monitoring of the sumps wall and fittings onthe secondary and tertiary walls. Reinforcement of walls become morecritical for these types of sumps with bottoms 302. A reinforced foamand/or fiberglass interstitial spacing 304 is utilized.

[0103]FIG. 12 illustrates an interstitial wall structure for a tank sumpwith a manometer 305 connected in fluid communication to theinterstitial structure 302. Also to avoid hydraulic forces lifting thetank sump a foam 306 is injected between the tank collar 307, tank 300and bottom 302 of the tank sump 301. As the foam bonds to the surface ofthe sump, tank and collar the forces are directed horizontally. Thehorizontal force from all sides would essentially cancel out itselfsince the force is pointing inward as opposed to an upward lift.

[0104] Some variations of manometers/sensors which are part of theinvention are described below. A tertiary containment sump for dispenseror tank sumps with interstitial 401 can be provided. A manometer kit canbe provided separately and be installable in the field. Other variationspermit filling the manometer and vent liquid through a single fill point402 probably at the highest point in the tertiary containment sump. Thefilling of the interstitial may be slowed and testing/trouble shootingusing air pressure or vacuum or helium is more difficult since theinterstitial is more difficult to drain.

[0105] Sensors and monitoring of dispenser containment ideally requiresa fail safe, fail to alarm, sensor or form of positive shutdown to stopa leak that is detected inside the secondary containment. In a tertiarycontained dispenser containment the box illustrated in FIGS. 13 and 14such a system is provided. In FIG. 13 there is an electronic sensor 403or mechanical system 404 to control leaks inside the box.

[0106] In one preferred form of with this invention one can visuallytest/and or monitor a sump. In another form of this invention adoptselectronic forms of monitoring/testing. One of the walls may includesensors to relate a drop in the interstitial fluid level or a change inthe interstitial condition. In FIG. 14 the use of the manometer 502 intertiary containment is adapted to use the manometer fluid tomechanically trip or close a shear valve 503 to stop the leaking supplypipe. A designer can use the physics of the hydraulic level dropping toactuate a mechanical device 501.

[0107] Many different types of sensors could be installed in themanometer to continuously monitor the level. A sensor can use a float tomonitor whether the level has dropped below a specific level. The sensormay be immersed in the interstitial fluid to reduce false alarms byallowing for changes in level due to expansion and contraction of air,shifting of pea gravel around the tertiary containment, evaporation, andtemperature changes in the interstitial. Another reasons for immersionof the sensor is to reduce the chances the float will not be exposed theelements that can lead to the float getting frozen so it will notcommunicate an alarm.

[0108] The sensors are ultimately connected to a module that receivesthe sensor signal and utilizes that information to perform an action,They will range from notifying, audibly or visually, the user that thecontainment system lost in integrity of either secondary/tertiary wallor shut off the power to the dispenser or shut off tanks submersiblepump that supplies the dispenser with product.

[0109] While the specification describes particular embodiments of thepresent invention, those of ordinary skill can devise variations of thepresent invention without departing from the inventive concept.

What is claimed is:
 1. A sump comprising: a base; a wall directedupwardly from the base of the sump towards a top thereby forming acavity; and the upwardly directed wall including an angular portionbeing directed at an angle from the base greater than 90 degreesrelative to the base and a remote location of that portion beingconnected with an substantially upright wall portion for the sump.
 2. Asump as claimed in claim 1 wherein the angular portion extending betweenthe base and the substantially upright wall portion extends at about 135degrees relative to the base and at about 135 degrees relative to anupright wall of the sump.
 3. A sump as claimed in claim 2 including anaperture through the angular portion.
 4. A sump as claimed in claim 3wherein the aperture includes a fitting for receiving a conduit, theconduit being directed substantially at right angles to the angularportion and the conduit including a bend within the sump, the bend beingfor directing the conduit substantially upwardly and parallel to aupright wall of the sump.
 5. A sump as claimed in claim 3 including abend in the conduit, the bend being in a position removed from thefitting and outwardly located relative to the sump such that the conduitportion after the bend is directed substantially parallel to the base ofthe sump.
 6. A sump as claimed in claim 4 including a bend in theconduit, the bend being in a position removed from the fitting andoutwardly located relative to the sump such that the conduit is directedsubstantially parallel to the base of the sump.
 7. A sump as claimed inclaim 4 wherein the conduit is integral and continuous between aposition removed from the sump and crossing through an aperture in thesump and upwardly in the sump.
 8. A sump as claimed in claim 1 whereinthe cross section of the sump viewed from the top is substantiallyrectangular.
 9. A sump as claimed in claim 1 wherein an end view of thesump includes a substantially horizontal top, a vertical side wall, thebase extending substantially parallel to the top and for a distancepartially equal to the distance of the top, and the angular portionextends upwardly to a line about equal to the end of the top, and avertically directed relatively shorter upwardly directed wall extendingbetween the end of the top and the end of the angular portion remotefrom the base.
 10. A sump as claimed in claim 1 including at least oneaperture in the upright wall, the aperture being to receive a pipecontaining fluid and for directing the pipe through the sump wall andupwardly to a position above the sump, the upright wall being the wallnot directly connected to the angular portion of the sump.
 11. A sump asclaimed in claim 10 including an aperture in the angular portion, theaperture being in a position relatively closer to the upright wallconnected to the angular portion than to the position of joinder of theangular portion with the base.
 12. A sump as claimed in claim 1 whereinat least one of the base or the wall of the sump is formed by at leasttwo elements and include said interstitial space between the twoelements.
 13. A sump as claimed in claim 1 including a mouth of the sumpat the top, the mouth being for receiving a gasoline dispenser and meansfor passage through the sump of one or more pipes connecting thegasoline dispenser with the environment outside of the sump.
 14. A sumpas claimed in claim 13 wherein one pipe is for directing gasoline froman environment outside of the sump through the sump and to the dispenserand including a conduit for directing electrical conductors from anenvironment outside of the sump through the sump to the dispenser.
 15. Asump as claimed in claim 14 wherein the gasoline pipe includes a portionvertically directed through the sump, and an elbow to direct the pipehorizontally, and a connector through a upright wall of the sump toconnect with the elbow, the connector being directed outside of the sumpfor connection to the environment beyond the sump.
 16. A sump as claimedin claim 15 wherein the electrical conduit includes a verticallydirected portion, a portion angled at about 135 degrees relative to thevertical portion and passing through an aperture in the angular portionof the sump, and a further bend in the conduit of about 135 degrees at aposition remote and outside of the sump, the conduit being for directingelectrical conductors from outside of the sump through the sump andabove the sump.
 17. A sump comprising: a base; a wall directed upwardlyfrom the base of the sump towards a top thereby forming a cavity; theupwardly directed wall including an angular portion being directed at anangle from the base greater than 90 degrees relative to the base and aremote location of that portion being connected with an substantiallyupright wall portion for the sump, and a mouth of the sump at the top,the mouth being for receiving a gasoline dispenser and means for passagethrough the sump of one or more pipes connecting the gasoline dispenserwith the environment outside of the sump.
 18. A sump as claimed in claim17 wherein the angular portion extending between the base and thesubstantially upright wall portion extends at about 135 degrees relativeto the base and at about 135 degrees relative to an upright wall of thesump; and an aperture through the angular portion, and the aperturebeing for receiving a fitting for receiving a conduit, the conduit beingdirected substantially at right angles to the angular portion.
 19. Asump as claimed in claim 18 including bends in the conduit, the bendsbeing at positions removed from the fitting.
 20. A sump as claimed inclaim 18 wherein the conduit is integral and continuous between aposition removed from the sump and crossing through an aperture in thesump and upwardly in the sump.
 21. A sump as claimed in claim 17 whereinthe cross section of the sump viewed from the top is substantiallyrectangular, and wherein an end view of the sump includes asubstantially horizontal top, a vertical side wall, the base extendingsubstantially parallel to the top and for a distance partially equal tothe distance of the top, and the angular portion extends upwardly to aline about equal to the end of the top, and a vertically directedrelatively shorter upwardly directed wall extending between the end ofthe top and the end of the angular portion remote from the base.
 22. Asump as claimed in claim 17 including at least one aperture in theupright wall, the aperture being to receive a pipe containing fluid andfor directing the pipe through the sump wall and upwardly to a positionabove the sump, the upright wall being the wall not directly connectedto the angular portion of the sump.
 23. A sump as claimed in claim 17including an aperture in the angular portion, the aperture being in aposition relatively closer to the upright wall connected to the angularportion than to the position of joinder of the angular portion with thebase.
 24. A sump as claimed in claim 17 wherein one pipe is fordirecting gasoline from an environment outside of the sump through thesump and to the dispenser and including a conduit for directingelectrical conductors from an environment outside of the sump throughthe sump to the dispenser, and wherein the gasoline pipe includes aportion vertically directed through the sump, and an elbow to direct thepipe horizontally, and a connector through a upright wall of the sump toconnect with the elbow, the connector being directed outside of the sumpfor connection to the environment beyond the sump.
 25. A sump as claimedin claim 24 wherein the electrical conduit includes a verticallydirected portion, a portion angled at about 135 degrees relative to thevertical portion and passing through an aperture in the angular portionof the sump, and a further bend in the conduit of about 135 degrees at aposition remote and outside of the sump, the conduit being for directingelectrical conductors from outside of the sump through the sump andabove the sump.
 26. A sump comprising: a base; a wall directed upwardlyfrom the base of the sump towards a top thereby forming a cavity; theupwardly directed wall including an angular portion being directed at anangle from the base greater than 90 degrees relative to the base and aremote location of that portion being connected with an substantiallyupright wall portion for the sump; a mouth of the sump at the top, themouth being for receiving a gasoline dispenser and means for passagethrough the sump of one or more pipes connecting the gasoline dispenserwith the environment outside of the sump; and an aperture through theangular portion, and the aperture being for receiving a fitting forreceiving a conduit, the conduit being directed substantially at rightangles to the angular portion, and bends in the conduit, the bends beingat positions removed from the fitting.
 27. A sump as claimed in claim 26wherein the angular portion extending between the base and thesubstantially upright wall portion extends at about 135 degrees relativeto the base and at about 135 degrees relative to an upright wall of thesump,
 28. A sump as claimed in claim 26 wherein the conduit is integraland continuous between a position removed from the sump and crossingthrough an aperture in the sump and upwardly in the sump.
 29. A sump asclaimed in claim 26 including at least one aperture in the upright wall,the aperture being to receive a pipe containing fluid and for directingthe pipe through the sump wall and upwardly to a position above thesump, the upright wall being the wall not directly connected to theangular portion of the sump, and an aperture in the angular portion, theaperture being in a position relatively closer to the upright wallconnected to the angular portion than to the position of joinder of theangular portion with the base.
 30. A sump for location below a groundlevel and for cooperation with a tank sump for storing gasoline forsubsequent delivery to a gasoline dispenser comprising: a base; a walldirected upwardly from the base of the sump towards a top therebyforming a cavity; and the base being for location on a tank sump collar,the collar giving access to tank sump for storing gasoline.
 31. A sumpas claimed in claim 31 wherein at least one of the base or the wall ofthe sump is formed by at least two elements and includes saidinterstitial space between the two elements.